Science

Prehistoric civilization have always been the talk of the town, and it's no wonder - after all, humans have been around for so short a time in the history of the planet that if we were to compress the history of the planet into a single day, then humans would probably only appear in the last two minutes of that day. In the past, there have been frequent claims of the discovery of suspected prehistoric civilization, the most notable of which would be a two-billion-year-old nuclear reactor.

If someone asks the question, are humans alone in the universe? I believe that most people would answer in the negative. In fact, the scientific community also generally agrees that there are a large number of intelligent civilisations in the vast universe, some of which may even be far ahead of our civilisation, and in order to better describe the technological level of intelligent civilisations in the universe, scientists have also proposed the concept of "Cosmic civilisation levels".

Since gravity is actually a manifestation of gravity, and the magnitude of gravity is proportional to mass, for those objects with smaller masses, their own gravity is smaller

Scientists using modern observation equipment have determined the size, position, distance and other data of most of the objects in our galaxy

Although ultra-pure water does not exist in nature, humans can prepare it themselves

The law of conservation of momentum means that the total momentum of a system remains constant when it is not subject to external forces or when the sum of the vectors of external forces is zero

The universe is so unimaginably large that even if humans were able to travel at infinitely close to the speed of light, they would not be able to penetrate its mysteries. Fortunately, the speed of light is not the speed limit of the universe, so it is entirely conceivable that in the distant future, humans may somehow be able to escape the shackles of the speed of light.

In essence, sound is actually a wave generated by the vibration of the object, the sound waves in the air is actually a "longitudinal wave"

The reason we don't see time travelers is actually because they are not in our timeline

In a good night sky, we can always see a sky full of stars and it seems to us that the whole universe is in full view. In fact, the stars we see in the night sky are only a tiny part of the milky way galaxy, which is just one of the trillions of galaxies that exist in the observable universe.